Compressor control



Aug. 30,1927. ,5

N. A. CHRISTENSEN v COMPRESSOR CONTROL Filed Sept. 17. 1926 2 Sheets-Sheet 1 I N VEN TOR.

A TTORNEYS Aug. 30 1927.

N. CHRISTENSEN COMPRESSOR CONTROL Filed Sept. 17. 1926 2 Sheets-Sheet 2 INVENTOR.

A TTORNEYJ' Patented Aug. 30, 1927.

UNITED STATES NIELS A. CHRISTENSEN, OF CLEVELAND, OHIO.

COMPRESSOR CONTROL.

Application filed September 17, 1926. Serial No. 138,158.

The invention relates to compressed air systems and more particularly to a governor or control of a continuously running compressor.

The general object of the invention is to improve upon the compressor overnor shown and described in my copen ing application Serial No. 707,536, filed April 18, 1924, by simplifying the arrangement of the parts, relieving the operating or hammer 1 member of lateral strains, using a single spring associated with said hammer member in a novel manner to assure uniform tension and prevent any possibili'ty of the binding of the hammer member during its movement, and to generallyimprove upon the aforesaid construction so that the parts may be readily made on a-quantity production basis and readily assembled so as to operate Withinclose limits without special fitting adjustments.

A further object of the invention is to provide a control mechanism in which the valve-holding latches and their actuator are disposed in substantially the same operating plane so asto provide a compact and efficient construction. r The invention further consists in the several featureshereinafter set forth and more particularly defined by claims at the conclusion hereof.

In the drawings Fig. 1 is a view of a compressed air system equipped with thegovernor embodying the invention;

Fig. 2 is a detail sectional view of the governor embodying, the invention, taken on the line 2-2 of Fig. 4, showing the mechanism holding the valve controlling passage to atmosphere open;

-Fig. 3 is a similar sectional view showing parts of the governor in position for normal compressor operation;

Fig. 4 is a plan view of the governor with the top cover removed;

. Fig. 5 is a detail sectional view taken on Fig.6 is a view snnilar to 2, showing a modification of certain of the parts.

Fig. 7 is a plan view of the governor shown in Fig. 6 with the top cover removed.

In Fig. 1 I have shown a compressed air system embodying a compressor 6 whose shaft 7 is continuously driven, said compressor being provided with the usual -d1scharge valve; not shown, past which the air is forced through a pipe S to the supply the line 5-5 of Fig. 2. i

tank or reservoir 9, a check valve 10 being provided in the pipe 8. This supply tank 9 may be used to supply compressed air through a pipe 11 for any useful purpose but more especially to furnish air for the starting or braking system of an automotive vehicle in which instance the compressor is mounted on a supporting member 12 of part of the vehicle and is driven through suitable connections by the propelling motor for such vehicle.

In Fig. 2 I have shown a compressor cylinder 13, the piston 14 working therein, the head 15 and the automatic or suction inlet valve 16 of the compressor which is acted upon by the governor to control the output of the compressor.

Inlet valve 16 is here shown as of the poppet type controlling passage of air to and .from the inlet port 17 into the cylinder 13 and normally urged to a closed position by a spring 18 interposed between the fixed guide bushing 19 for the stem of said valve and a collar 20 pinned or otherwise suitably secured to said stem. I

The governor includes a main support 21 which has laterally extending apertured lugs 22 through which bolts 23 pass into the head of the compressor to secure said support 21 to the compressor. This support has spaced uprights 24 projecting from its base and carrying a pin 25 upon which the operating lever or hammer member 26 working between the upright-sis pivotally mounted.

The member 26 is operated by a rod 27 which has a square forked upper end 28 whose bifurcations extend on opposite sides of the lever and carry a transverse pin 29 extending through a square hole 30 in said lever, said hole being larger than the pin to provide a lost motion connection so that said hammer member may be quickly moved-past its dead center. position as hereinafter described. The square end 28 of the lever works in a square slot formed by recesses 31 in exportion of the tensions of the uprights 24 and has a running fit therein so as to prevent any side thrust of said forked end 28, and the bifurcations of said end are out of contact with the lever orhammer 26so that all tendency for binding at the connection between the rod 27 and the lever 26 is prevented.

To provide for a quick and powerful throw of the lever 26 a springv 32 is, provided. This spring is operatively connected to the lever 26 by telescoping members 33 and 34. The member 32 is connected by a pin 35 to the end of the lever 26 adjacent the hole 30 and has a tubular portion 36 slidably mounted in a bore 37 of the member 34 which is mounted at its outer end upon a pin 38 carried in uprights 39 onthe main su port 21, the spring 32 being mounted in a bore 39 of the tubular portion 36 of the member 33 with one 'end engaging thebottom of said bore and the other end engaging the bottom ofthe bore 37.

With this construction when the lever 26 is moved from the position where the centers of the pins '25, 35 and 38 are in line, the spring 32, which has been compressed at the time these centers were in line, will, because of the-lost motion connection hereinbetore described, cause the lever 26 to be moved quickly out of the line of centers and, as hereinafter described, this movement to one side or the other of the line of centers is adapted either to hold the inlet valve open when the'maximum desired pressure oi compressed air has been reached in the system or to permit the inlet valve to function normally when the desired minimum pressure in the system has been reached. I The rod 27 is moved in one direction, that is, upwardly, by fluid-pressure-operate means comprising a cap member 40 working in a casing 41 and with which the lower threaded end of said rod engages, said cap member forming with a plate 42, secured to the casing 41, and a sylphon bellows 43 connected at one end to said ca and at its other end to said plate ina flui -tight manner, a pressure chamber 44 in communication with the reservoir 9 through a port 45 and a pipe 46 leading to said reservoir.

Thus, when air is introduced into the chamber 32 it will tend to move the .cap 40 upward and hence move the rod 27 upward and cause the end of the lever 26 with which it is connected to swing upward past its fulcrum center andthe spring 32 which has been laced under-increased compression as the pins 25, 35 and 38 move to a dead center positionthen causes the free end of the lever '26. to move down quickly the amount of'lost motion, as shown in Fig. 2.

The'.casin member-41 has laterally disosed lugs 4 and screws 48 extend through ugs 40 on the main support 21 into the lugs 47 to secure the casing 41 and the parts associated therewith in assembled position.

The rod 27 is moved in the o posite direction by a s ring 50interpose between the bottom of t e support 21 and a seating disk 51 on the rod adjustably secured thereto by a nut 52. The spring 50causes said rod to move downwardly in opposition to pressure 0 of air in the chamber44-and when the spring pressure predominates this causes the end of the lever 26 with which it is connected to swing downward past dead center position 'In order to hold the inletvalve 16open when maximum reservoir pressure has been reached, a pair of spring-pressed latches 54 and 55 are provided, operatively associated with the hammer member or lever 26. The latch 54 is disposed within the space between the uprights 24 below the lever 26 and a recess 54 in the support 21, and is pivotally mounted upon a pin 56 carried by said uprights and is normally moved to a release position by means of a spring 57 mounted in a bore in the main support 21 and acting on a tubular member or plunger 58 slidably mounted in said here and engaging the latch. The release position of the latch 54 is deter mined by a stop pin 59 projecting up from the recess 54' in the support 21 in which a part of the latch 54 Works and engaged by a 1 stop projection 60 on said latch when in release position, as shown in Fig. 3.

The latch 55 is pivotally mounted on a. pin 61 extending through a bore in the support 21 and provided with notch 62 with which the pointed end 63 ot' the latch 54 engages, whereby the latch 55 holds the latch 54 in inlet-valve-holdingposition. The latch 55 is normallym'oved so as to lockingly engage the latch 54 by means of a coil spring 64 mounted in a recess 65 in the support 21 and V secured at one end to said latch 55 and atits other end to the support. .The free end of the latch 54 projects over the top end of the inlet valve 16 so as to engage the same and either move it downwardly or move down to hold the valve open during the suction stroke of the compressor, and in either casewhen said inlet valve is in an open position the latch 54 has been moved downwardly to an extent permitting the spring-pressed latch 55 to snap over the pointed end 63 of the latch 54 and thus hold the latch 54 in a position to maintain the inlet valve open. The latch 54 v is made to assume this position by the free end 53 of the lever 26 striking said latch and.

moving it downwardly when, as previously described, the pressure in the reservoir and hence in the chamber 44 exceeds the opposing pressure of'the spring 50. i

hammer member 26 moves upwardly, as

previousl described, and'as the latch 55 has its curve or bevelled end 66 in the path of movement of said lever or hammer member 26 the sa'meis engaged by said lever upon its upward swinging movement so as to release said latch 55 from locking engagement with the latch 54 and thus allowthe inlet system, the latches 54 and 55 engage with.

each other and hold" the inlet valve open, and under these conditions the piston of the compresso fl'ceases" to function as such and simplygggdrawsjnaand pushes out the air throughthe inlet port 17 until such time as the pressure in the system has dropped to such'a point-that the spring 50 overcomes the pressure in the chamber 44 and then the free end 53 of the lever 26 is given a quick upward movement, causing the release of the latch 55 from the latch 54: so that the inlet valve of the compressor is free to operate normallyand supply atmospheric air to the compressor which then functions normally to supplythe tank 9 with compressed air until the pressure reaches the desired maximum value,and then the action of holding the inlet valve open is again repeated, it being noted that the single spring 32 and its association with the lever 26 causes a quick hammer blow to be dealt by the lever 26 alternately to the latches 54 and 55, depending upon conditions of maximum or minimum pressure.

A cover member 67 encloses the mechanism above the support 21 and has its lower edge held down against the support by means of a knurled nut 68 mounted upon a stud 69 projecting from one of the uprights 24, and the width of this cover andthe length of the pins 25, 38 and 56 are such that the sides of said cover member almost touch the ends of these pins so that said pins are prevented from longitudinal movement by the cover without the use of any additional fasteningmeans.

The pin. 61 has a head 70 at one end and" is held against longitudinal movement by i a cotter pin 71 at the other end;

The construction shown in Figs. 6 and? is identical in many respects with the construction previously described and similar parts have been similarly referenced and act in the same way as those previously described. The modification consists in providing a single tension spring 72, secured at one end to a pin 73 on the latch 55 and at its other end to a fpin 74 on the latch 54 to take the place 0 the springs 57and 64 in that this single spring 72 acts to normally keep bothlatches in locked position, as shown in Fig. 6, when the pressure is a maximum, but said latches do not in-' terfere with the normal operation of the compressor inlet. valve when the'lever 26 is in its upper position, as shown in Fig. 3.

From Fig. 7 it will be noted that the spring 72- 1s offset relative to the inlet valve, so as not to interfere with its movement, and

readily made in quantities and more .-easily assembled. than. the construction shown? and described in my above mentioned application, and that it will work efliciently within the limits of maximum and minimum pressures desired in servlce.

While I have described the governor as sor, it will be understood that it may also be used on a relief valve separate from the inlet valye without any change in the governor or mode of operation of the compressor from that herein described, it being noted that "it. is simpler to have the inlet valve act as a relief valve than to provide an additional relief valve.

I desire it to be understood that this inventionvis not to be limited to any particular form or arrangementzof parts except insofar as such limitationsare specified in the claims.

What I claim as my invention is:

1. In a compressor control, the combination with a compressor and the systemsupplied thereby, said compressor having a valve controlling passage to atmosphere, of mechanism for controlling the operation of said valve while the compressor is running, comprising a pair of latchesllockingly engageablewith each other to hold said valve open, a hammer member for moving said latches to locked position to hold said valve open under conditions of maximum pressure in said. system to prevent said compressor from functioning and for releasing said latches undercondltions of minimum preshammer member including a member having lost motion connection with said hammer acting'upon the inlet valve of the compressure in'said system to permit said compresmember, and a single spring associated with said hammer member to impart a quick throw thereto upon the occurrence of max1- mum or 'mlmmum pressure conditions in.

' said valve including a-pair of latches, a pivoted' hammer. member for actuating said latches, means responsive to pressure changes (1 system to actuate said hammer 30 in sai p member lncludmg a rod out of contact with said member to relieve it of lateral strain, and guide means for said rod insuring its out-of-contact relation with said hammer member. i

3. In a compressor control. the combination with a compressor and the system. supplied thereby, said compressor having a valve controlling passage to atmo'sphere,--of

mechanism for controlling the operation of said valve including a pair of pivotally mounted spring-pressed latches for holding said valve open, a support having a pair of spaced uprights between which one of said latches is pivotally mounted, a latch-operating member pivotally mounted between said uprights above said last-named latch, of means responsive to pressure Changes. in said system for actuating said operating member and causing it to deliver a hammer blow to one of said latches in one position to lock said latches together in valve-holding position to prevent said compressor from functioning and to deliver a hammer blow in another position to the other latch to release said latches from valve-holding position and thereby permit said compressor to function.

4. In a compressor control, the combination of a pair of pivotally mounted springpressed' valve-holding latches disposed in substantially the same operating plane, a latch-actuating member disposed in the same plane, and means responsive to pressure changes in the system supplied by the compressor for moving said member to effect engagement of said latches in a valveholding position under conditions of maximum pressure in said system and to effect release of said latches from a valve-holding position under conditions of minimum pressure in said system. a v

5. In a compressor control, the combination of a pair of pivotallv mounted springpressed valveholding latches disposed in substantially the same operating plane, a latch-actuating member disposed in the same plane, means responsive to pressure changes in said systems for moving said member to actuate said latches to govern the output of the compressor, and a spring disposed in the same plane as said member for accelerating its movement.

6. In a compressor control, the combination of valve-holding means including a pivtion of a pair of valve-holding latches, a

hammer member for actuating said latches, a single spring acting on one end of said lever, a member responsive to pressure changes in the system supplied by the compressor and having a lost motion operating connection with said hammer member whereby said spring acts to accelerate the movement of said hammer member upon its movementto either side of its dead center position.

8. In a compressor control, the combination of a pair of valve-holding latches. a pivoted hammer member for actuating said latches, a support for said latches and member, a pair ofslidably associated members operatively connected respectively with said hammer member and said support, a spring for moving said slidable members relative to each other and thus imparting a quick movement to said hammer member, and means, responsive to pressure changes in the system supplied by said compressor for compressing said spring so that it may release its energy to said hammer member when said hammer member moves to either side of its dead center position. i

9. In a compressor control, the combination with a compressor and the system supplied thereby, said compressor having a valve controlling passage to atmosphere, of mechanism for controlling the operation of said valve while the compressor is running comprising a pair of latches lockingly engageable with each other to hold said valve open a single spring associated with said latches, and means responsive to pressure changes in said system for bringing said latches to valve-holding position under conditions of maximum pressure in said system and for permitting said valve to function normally under minimum pressure conditions in said system.

In testimony whereof, I afiix my signature.

NIELS A. CHRISTENSEN. 

